MSDeploy Powershell Scripts Part II – Exceptions And Remote Server Syncs

In this blog I will show how to script syncing remote servers and add some useful exception handling.  This blog assumes you have read or are familiar with part I at:

http://blogs.iis.net/jamescoo/archive/2009/09/09/cool-msdeploy-powershell-scripts.aspx

For MSDeploy API examples visit here:

http://blogs.iis.net/jamescoo/archive/2009/11/03/msdeploy-api-scenarios.aspx

First a borrowed function that will help implement a try catch block in the script-let logic from part I.  This will allow for MSDeploy exceptions to be caught and reported making life a bit easier when you get an error.  The code is from:

http://weblogs.asp.net/adweigert/archive/2007/10/10/powershell-try-catch-finally-comes-to-life.aspx

Simply paste this into the Powershell session ( or start all these functions in your profile ) and you are ready to use try catch blocks:

function Try
{
    param
    (
        [ScriptBlock]$Command = $(throw "The parameter -Command is required."),
        [ScriptBlock]$Catch   = { throw $_ },
        [ScriptBlock]$Finally = {}
    )
    & {
        $local:ErrorActionPreference = "SilentlyContinue"
        trap
        {
            trap
            {
                & {
                    trap { throw $_ }
                    &$Finally
                }
                throw $_
            }
            $_ | & { &$Catch }
        }
        &$Command
    }

    & {
        trap { throw $_ }
        &$Finally
    }
}

Visiting back to part I, the most versatile script-let was the Sync-Provider so next is to add exception handling to this script-let.  Of course, not to forget to load the assembly first (hopefully this is now part of your Powershell profile ).

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.Web.Deployment")
function Sync-Provider($provider, $sourceLocation, $destLocation) 
{ 
    $destBaseOptions   = new-object Microsoft.Web.Deployment.DeploymentBaseOptions 
    $syncOptions       = new-object Microsoft.Web.Deployment.DeploymentSyncOptions 
    Try
    {
      $deploymentObject = [Microsoft.Web.Deployment.DeploymentManager]::CreateObject($provider, $sourceLocation) 
      $deploymentObject.SyncTo($provider,$destLocation,$destBaseOptions,$syncOptions)
    }
    Catch
    {
      echo "EXCEPTION THROWN::[ $_ ] "
      #throw $_
    }
} 

 

Now that you have better exception handling you can get messages like this ( in this case you cannot sync a site to a directory with apphostconfig provider ):

>  Sync-Provider apphostconfig "Default Web Site" c:\mysite

EXCEPTION THROWN::[ Exception calling "SyncTo" with "4" argument(s): "Invalid site name
" ]

In order to perform remote server syncs, credentials will have to be included with the name of the machines that you want to sync.  To do this I decided to go with the below functions to help store remote machine information.  ‘Create-Server’ will make a new file that will be saved on the local system drive ( feel free to change where you are storing these but you must also change Sync-Server respectively ) with the same name as the computer name being stored.  The credentials will be saved and the password will be converted to a secure and then encrypted into the same file.

#load and run this function for each server you would like to perform a remote sync operation on

function Create-Server()
{
  Try
  {
    $machine = "" | select ComputerName,UserName,Password
    $machine.ComputerName = Read-host -prompt "Machine name"
    $fileName = $machine.ComputerName
    $machine.UserName    = Read-host -prompt "User name"
    $machine.Password = Read-host -prompt Password -assecurestring | convertfrom-securestring
    $machine | Export-Csv $Env:SystemDrive\$fileName.txt
  } Catch {
      echo "EXCEPTION THROWN::[ $_ ] "
  }  
}  

 

 

 

The next function will help us later when converting the secure string to plain text, this snippet is from a forum reply at:

http://www.vistax64.com/powershell/159190-read-host-assecurestring-problem.html

Function ConvertTo-PlainText( [security.securestring]$secure )

{
   $marshal = [Runtime.InteropServices.Marshal]
   $marshal::PtrToStringAuto( $marshal::SecureStringToBSTR($secure) )
}

The next function Sync-Server will take a provider as a string, then the name of two machines that you want to sync.  It will then match the names of the machines to corresponding files on the local box and import the original objects that are exported in “Create-Server”, then convert the encrypted password so it can be used by msdeploy.  Examples of usage are farther down:

function Sync-Server($provider, $source, $dest)
{
  Try
  {
    #read from files
    $sourceMachine = Import-Csv $Env:SystemDrive\$source.txt
    $destMachine = Import-Csv $Env:SystemDrive\$dest.txt
  }
  Catch
  {
    echo "EXCEPTION THROWN::[ $_  ] "
  }
    $destBaseOptions   = new-object Microsoft.Web.Deployment.DeploymentBaseOptions
    $sourceBaseOptions   = new-object Microsoft.Web.Deployment.DeploymentBaseOptions
    $syncOptions = new-object Microsoft.Web.Deployment.DeploymentSyncOptions

    #fill in remoting information for source machine
    $sourceBaseOptions.ComputerName = $sourceMachine.ComputerName
    $sourceBaseOptions.UserName = $sourceMachine.UserName;
    $password = ConvertTo-SecureString $sourceMachine.Password
    $password = ConvertTo-PlainText $password
    $sourceBaseOptions.Password = $password

    #fill in remoting information for destination machine
    $destBaseOptions.ComputerName = $destMachine.ComputerName
    $destBaseOptions.UserName = $destMachine.UserName;
    $password = ConvertTo-SecureString $destMachine.Password
    $password = ConvertTo-PlainText $password
    $destBaseOptions.Password = $password

  Try
  {
    $providerOptions = new-object Microsoft.Web.Deployment.DeploymentProviderOptions($provider)
    $deploymentObject = [Microsoft.Web.Deployment.DeploymentManager]::CreateObject($providerOptions, $sourceBaseOptions)
    $deploymentObject.SyncTo($destBaseOptions,$syncOptions)
  }
  Catch
  {
    echo "EXCEPTION THROWN::[ $_  ] "
  }
}